Landing chassis for aircraft



Nov. 3, 1925.

A. ROHRBACH LANDING CHASSIS FOR AIRCRAFT Filed Sept. 5, 1921 2Sheets-Sheet l Nov. 3, 1925.

A. ROHRBACH LANDING CHASSIS FOR AIRCRAFT Filed Sept. 5. 1921 2Shank-Shed. 2

INVE NTOR: W W

A Ahdi 8 akin/mug.

Patented Nov. 3, 1925.

UNITED STATES PATENT OFFICE.

Application filed September 8, 1881. Serial No. 488,308.

To all whom it may concern:

Be it known that I, Anonr Romznaon, a citizen of Germany, residing atBerlin- Charlottenburg, Germany, have invented certain new and useful Imrovements in Lending Chassis for Aircra (for which I have filedapplications in Germany, June 10, 1919 July 2 1920, and February 14,1921), of which e following is a specification.

\ exerted on the gear without detracting from this man its ability toreturn to normal position.

These objects are attained according to my invention with a landin gearin which the wheels are not moun on a common axle but each wheel is freeto turn resiliently about an axis rigidl connected with the hull andextending at east approximate] in the longitudinal axis of the craft.ith ent each axis of oscillation lies substantia ly outside the axis ofthe wheel, so that the wheel, on swinging upwards, at the same timeswings laterally. As it is only essential for the articular object to beattained, that the rec 'ng axis which extends lpreferably at rightangles to the wheel axle, as a fixed position in relation to the 'hull,there may be cognected for instance to the lower part of the hull asubstantially triangular support extending in parallel to the ongitudmaldirection of said body, which, at one corner, carries the wheel axle andis hinged to the hull in two axially ali ed points, means being providedfor resiliently counteractin rockin motion of this support and the w eelcarried by it.

A particularly simple and reliable arrangement is obtained if two strutsconverging towards the wheel are used for support ing the wheel axle,their free diverging ends bemg hinged to the hull in such manner thattheir relative position is invariable, while they are capab e, ofswingin about a. fixed (aixis extending in arallel to t efdirefitin ofriving, againstt e resistance 0 a i resilient strut.

The oints, in which the resilient struts referre to engage the wing, andtheir inclination relatively to the wing are so chosen that the wingbases are relieved from strain near the body of the craft and aminimumof stress is pro need when landin k The wing thus obtains the c aracterof a girder supported in two Ipoints, that is, by the two resilientstruts. t may conse uently be designed much lighter than if, as in theconstructlons heretofore used, the wing base in landing has to transmitall the forces tending to bend the wing onto the hull from which theyare transmitted to the landin gear. The moment curve is thereby consierably changed.

I may further employ one of the rocking struts as wheel axle, this beingpossible articularly in the case where the two roc 'ng struts extend inan approximately horizontal plane.

As a rule, favourable conditions will be obtained with a proximatelyhorizontal rocking struts an vertical resilient struts, but it may bepreferable to more or less incline the resilient struts.

The a proximately horizontal struts may further e designed to form stumpwi s. I am aware that it is old, to so design t e axles of a normallanding chassis or to provide them with a casing of such form that itwill act as a stump wing. As compared with this arran ement thehorizontal rocking struts invo ve remarkable advanta es particularly inrelation to a simplification of design. In the constructions heretoforeknown many constructional difliculties preseted themselves whichrendered the arrangement of wing sections as casings for the axles ofthe landing gear very diflicult. In the landing gear according to thepresent invention these difficulties are overcome. The casing can bearranged withngt paying attention to the motion of the springs inrelation to the struts and their bracing. The cas' will always 0 rate asa dynamic mem er. The an le 0 incidence to which it has been adjustswill be maintained under all conditions.

In the drawings aflixed to this specification, and forming part thereof,several devices embodying my invention are illustrated by way ofexample. In the drawings Fi 1 is a cross section of the body and landinggear of an aeroplane,

Fig. 2 is a side elevation, partly in section,

Fig. 3 is a front elevation of an aeroplane, inwhich the wheel axles ofthe wheels form the rocking struts,

Fig. 4 is the moment curve of this aeroplane at the moment of landing,

Fig. 5 is a corresponding curve for a strut not engaging the wing,

Fig. 6 18 an elevation illustrating the aplication of my invention to anaeroplane having two engines one on either side of the body.

Fi 7 is an elevation of an aeroplane in whdic the rocking struts formstump wings, an

Fig. 8 is a section on line 8-8 of Fig. 7.

Referring now to Figs. 1 and 2 each longron a of the hull a supports inball shaped oints 0. the free ends of two struts B, B which are rigidlyconnected with one another. At the point, where the two struts meet, theaxle of a wheel C is attached. This point further carries a ball hearingI) for the lower portion D of a strut consisting of two portions D and DThe upper portion of the strut is adapted to telescope in relation tothe other and is supported in the upper longron a of the all A b meansof a ball joint a. The portions 1 and D of the strut are under theaction of a spring in a casing E and tend to assume the positionillustrated in Fig. 1. However, when shocks are exerted in landing, theymay be di laced in relation to each other, so that t e distance a, b isshortened. Instead of ball joints, hin es might be used, which wouldhowever ren er an exact adjustment diflicnlt, which adjustmcnt, besides,would hardly be maintained in operation. The spring connecting theportions D D might also be entirely enclosed within the struts.

Referring now to Fig. 3, to the hall a are pivoted horizontal struts b,which carry the wheels 0. The struts b are maintained in position inrelation "to the hull by struts b, which, being disposed behind strutsb, are not visible in the drawings. These struts arc vertically bracedagainst the wing by means of struts d, in which there are insertedsprings e. In Fig. 6, the strut b is visible. the struts d engage strutb on the outside of the wheels 0 and the motor casing f from underneath.

Referring now to Figs. 7 and 8, the struts b ivoted to the body a andbraced in relation to the wings by the resilient struts 0 are encased ina stump win (1.

I- wish it to be understo that I do not desire to be limited to theexact details of construction shown and described, forobviousmodifications will occur to a person skilled in the art.

I claim:

1. A flying machine com rising a hull, two wheels, one on each Sid ofthe hull, mounted independently of one another, a substantiallytriangular support for each wheel carrying the wheel at one corner andhinged to the lower part of the bull in two axially aligned points andmeans for resiliently counteracting a rocking of said support about saidpoints.

2. A flying machine comprisin a hull, two wheels, one on each side ofthe hull, mounted independently of one another, two struts convergingtowards and carrying each wheel and having their diverging ends hingedto axially aligned points on the lower part of said hull and means forresiliently counteracting a rocking of said support about said points.

3. A flying machine comprisin a hull, two wheels, one on each side ofthe ull, mountcd independently of one another, a substantiallytriangular support for each wheel carryingthe wheel at one corner andhinged to the lower part of the hull in two axially ali ned points, awing on each side of the hu 1 and a resilient strut bracing said supportagainst a fixed point situated substantially on the level of said wing.

4. A flying machine com rising a hull, two wheels, one on each aid; ofthe hull, mounted independently of one another, two struts conver ngtowards and ca 'ng each wheel and avmg their diverging ends hinged toaxially aligned points on the lower art of said hull, a wing on eachside of the liull and a resilient strut bracing said support against afixed point situated substantially on the level of said wing.

5. A flying machine com rising a hull, two wheels, one on each si e ofthe hull, mounted independently of one another, a substantiallytriangular support for each 5 wheel carrying the wheel at one corner andhinged to the lower part of the hull in two axially aligned points, awing on each side of the hull and a resilient strut bracing said supportagainst said wing.

6. A flying machine com rising a hull, two wheels, one on each si e ofthe hull, mounted independently of one another, two struts converging,towards and carrying each wheel and having their diverging ends hingedto axially aligned points on the lower part of said hull, a wing on eachside of the ull and a resilient strut bracing said wheel carrying strutsagainst said wing.

7. A flying mac ine com rising a hull, two wheels, one on each side 0the hull, mounted independently of one another, a substantiallytriangular support for each wheel carrying the wheel at one corner andhinged to the lower part of the bull in two axially wheel and havingtheir diverging ends 10 aligned points, said support normally exhingedto axially aligned points on the tending in a substantially horizontalplane, lower part of said hull, said struts normally and means forresiliently counteraetlng a extending in a substantially horizontalrocking of said su port about said points. plane, and means forresiliently counteract- 8. A fl ing maclilne com rising a hull, mg arocking of said support about said'lfi two whee s, one on each side ofthehull, points. mounted independently of one another, two In testimonywhereof I aifix llgfisignature.

struts converging towards and carrying each DR. ING. ADOLF R0 BACH.

to the lower part of the hull in two axially wheel and having theirdiverging ends 1 aligned points, said support normally exhinged toaxiall aligned points on the tending in a substantiall horizontal plane,lower part of sai hull, said struts normally and means for resilient ycounteracting a extending in a substantially horizontal rocking of saidsu port about said points. plane, and means for resiliently counteract-8. A H ing maciilne com rising a hull, mg a rocking of said supportabout said 1 two whee s, one on each si e of thehull, points. mountedindependently of one another, two In testimony whereof I affix m siature. struts convergmg towards and carrying each DR. ING. ADOLF ROI-IlIB CH.

DISCLAIMER.

1,559,912.-Ad0lf Rolwbach, Berlin-Charlottenburg, Germany. LANDINGCHAssIs FOR AJRoRAr'r. Patent dated November 3, 1925. Disclaimer filedJanuary 12,

1928, by the patentee. Enters this disclaimer to said Letters Patent asfollows: I. To a flying machine as specified in each of the claimsexcept a flying machine of the monoplane type, and

II. To that part of claims 1,2, 7 and 8 reading as follows: meansfOIJ'GSlhEDfl counteracting the rocking of said support about saidpoints, except where suc means is interposed between the monoplane wingand the wheel support, as for example exemplified in Fig. 6 of thepatent drawings, and.;as d1st1ngu1shed for example from the structure ofFigs. 1 and 2 where such means is interposed between the hull and thewheel support. 4

[Oficial Gazette January 24, 1.928.]

DISCLAIMER.

1,559,912.Aalolf Rohrocwh, Berlin-Charlottenburg, Germany. LANDINGCHASSIS I FOR A'mcRAFr. Patent dated November 3, 1925. Disclaimer filedJanuary 12,

1928, by the patentee. Enters this disclaimer to said Letters Patent asfollows:

I. To a flying machine as specified in each of the claims except aflying machine of the monoplane type, and

H. To that part of claims 1 .2, 7, and 8 reading as follows: meansforlesilientl counteracting the rocking of said support about saidpoints, exeept Where sue means is interposed between the monoplane wingand the wheel support, as for example exemplified in Fig. 6 of thepatent drawings, andas distinguished for example from thestructure ofFigs. 1 and 2 where such means is interposed between the hull and thewheel support. I

[Ofiicz'al Gazette January 24, ].928.]

